Abstract
Motivated by improved limits on electric dipole moments (EDMs), we revisit the three-loop light-by-light mechanism that transmits CP violation from a heavy fermion to a light one. Applying it to the electron EDM induced by EDMs of heavier flavors, we find additional contributions at the order me/mμ or me/mτ that were missing before and that make the result 1.4 times larger. Consequently we improve bounds on the tau EDM, and update indirect limits on the muon EDM as well as charm and bottom quark color EDMs.
| Original language | English (US) |
|---|---|
| Article number | 137496 |
| Journal | Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics |
| Volume | 835 |
| DOIs | |
| State | Published - Dec 10 2022 |
Bibliographical note
Funding Information:Y.E. and M.P. are supported in part by U.S. Department of Energy Grant No. de-sc0011842 . Y.E. and M.P. would like to thank Perimeter Institute for the hospitality extended to them during the completion of this work. Y.E. would like to thank Yukinari Sumino for holding a spring school on multi-loop computation at Tohoku University in 2017. M.P. would like to thank Dr. K. Melnikov for the advice in evaluating loop contributions. The Feynman diagrams in this paper are generated by TikZ-Feynman [43] .
Funding Information:
Y.E. and M.P. are supported in part by U.S. Department of Energy Grant No. de-sc0011842. Y.E. and M.P. would like to thank Perimeter Institute for the hospitality extended to them during the completion of this work. Y.E. would like to thank Yukinari Sumino for holding a spring school on multi-loop computation at Tohoku University in 2017. M.P. would like to thank Dr. K. Melnikov for the advice in evaluating loop contributions. The Feynman diagrams in this paper are generated by TikZ-Feynman [43].
Publisher Copyright:
© 2022 The Author(s)